Broadband dielectric relaxation spectra (at 20 to 40 °C) are reported for three liquid alcoh ol/non polar solvent systems: Binary hexanol/mesitylene mixtures and two corresponding ternary mixtures, where 5 percent of hexanol are replaced by a dihydric alcohol, namely resorcinol (1,3-dihydroxyben zene) or 2,2'-dihydroxydiphenyl. The concentration of the polar substance(s) ranges from dilute solutions to pure alcohol(s). The lower frequency relaxation contribution, which generally is the more dominating the higher the alcohol concentration, is additionally enhanced by the diol admix ture in the case of low and moderate concentrations. This can be understood as a hetero-association effect, the diol m olecules playing a bridging role, which also leads to an increase in the mean lifetime o f associated states.